Brake mechanism for a reciprocating blade

ABSTRACT

A brake mechanism including a housing for attachment to a clipping machine with the housing serving to support both brake and clutch means with the latter coupled to the machines reciprocating blade by interconnecting arms. Rotational movement is imparted to a driving clutch member by said arms with the clutch being of the uni-directional type permitting unrestricted downward movement of the blade while in an opposite direction engaging a cooperating driven clutch member to ultimately initiate brake operation to accomplish a non-rebounding type return of the blade to its rest position.

United States Patent 91 Shaughnessy 5] Apr. 17, 1973 [5 BRAKE MECHANISMFORA 3,416,392 12/1968 Rutz ..83/526X RECIPROCATING BLADE [75] Inventor:P. Shaughnesy, Portland, jzz g gfig ggi g' t [73] Assignee: E. V.Prentice Co., Portland, Oreg. 57] ABSTRACT Filed! 1972 A brake mechanismincluding a housing for at- Appl. No.: 231,991

[52] U.S. Cl ..83/526, 83/630 [51] Int. Cl. ..B26d 5/18 [58] Field ofSearch ..83/526, 615, 630

[56] References Cited UNITED STATES PATENTS 2,221,877 11/1940 Meyer..83/526 2,783,843 3/1957 Seybold ...83/526 3,225,637 12/1965 Thumin..-.83/526 tachment to a clipping machine with the housing serving tosupport both brake and clutch means with the latter coupled to themachines reciprocating blade by interconnecting arms. Rotationalmovement is imparted to a driving clutch member by said arms with theclutch being of the uni-directional type permitting unrestricteddownward movement of the blade while in an opposite direction engaging acooperating driven clutch member to ultimately initiate brake operationto accomplish a non-rebounding type return of the blade to its restposition.

15 Claim, 7 Drawing Figures PATENTEB APR 1 7 I973 SHEET 1 BF 2 TQM ElNEED PATENTED 3 71975 3, 727. 505

SHEET 2 OF 2 36 OVR'N sue \QQ AGE BRAKE MECHANISM FOR A RECIPROCATINGBLADE BACKGROUND OF THE INVENTION The present invention relates to abrake mechanism for braking a reciprocated blade during one direction ofblade travel to precisely stop the blade at its rest position. While thebrake mechanism is presently shown and described in conjunction with awood veneer clipping machine such is not intended to imply its use isrestricted to any particular type of blade equipped machine.

In the production of wood veneer destined ultimately for lay up intolaminated plywood panels, the wood veneer ribbon passes a clipper whichis intermittently operated to sever the veneer into desired lengths.Additionally, the clipper also sections out unsuitable veneer segments.Originally, a machine operator visually inspected the passing veneeractuating the clipper blade as necessary. More recently clipperoperation is in response to automatic controls normally occurring atpredetermined intervals to provide the dimensions sought or, if need be,removing pitch pockets, knots, cracks, etc.,.

characteristically, the veneer lathe peeling the veneer ribbon from thepeeler log operated to produce veneer faster than a single clippermachine could handle same hence it is common practice to feed a pair ofclipping machines from one lathe or alternatively store the veneertemporarily for later clipping both of which entail considerableequipment and man hour cost.

In an effort to reduce the restrictive effect of the clipping operationon a veneer production line recent developments have included theintroduction of electronic scanning of the continuous veneer ribbon fordefects with electronic components initiating asignal for bladeoperation. Accordingly, an increase in the speed at which the veneerribbon could be presented to the clipper was realized, the speedpresently being approximately 300 feet per minute or five feet persecond. A limiting factor in veneer speed appears to be associated withthe momentary obstruction of veneer ribbon travel during cutting contactwith the blade.

Reducing the duration of contact between blade and veneer is desirablehowever, efforts to increase blade speed have been limited byobjectionable rebounding of the blade by reason of its forceful returnto its rest position. Efforts over the years to dampen rebounding haveincluded pneumatic dampeners for the blade actuating air cylinders whilestill other efiorts have included a friction drag in contact with ablade bar of the clipper for a portion of blade travel which undesirablyinhibited blade speed. Further, the results did not always provideuniforrn braking of the blade hence regular adjustment was required.

As the blade and associated moving linkage has considerable mass theinstantaneous starting and stopping imparts impact blows to the machineand the blade linkage resulting in machine depreciation. With clipperblade operations occurring several hundred times during a work shift, aprime advantage of a blade braking system is the avoidance of suchimpacts to the machine permitting accelerated blade speeds on thecutting stroke.

With existing scanning systems a time delay must be provided to enablethe scanned veneer to move under 0 As approximately nineteen percent ofall peeled veneer is cut away at the clipper operation the accuracy ofsuch clipping becomes important.

SUMMARY OF THE PRESENT INVENTION The present invention is adaptable forattachment to existing clipping machines or other types of machineswhere it is desirable to brake a reciprocating member in one direction.The present device is adapted for mounting on existing machines andincludes a unidirectional, overrunning clutch component to impart motionin one direction only to a brake means.

Importantly the present device permits an unrestricted, high speedcutting stroke of a clipper blade with the braking action of the devicebeing applied only during return of the blade to its rest position.Accordingly, an important advantage is realized in that blade speed atthe instant of veneer cutting is not in any way diminished as is thecase with former blade braking arrangements.

During the upstroke of the blade continuous braking is applied so as todissipate blade inertia and allow the blade to uniformly return to itsrest position with no rebound. A twofold benefit is realized, one beingthe avoidance of an impact blow to the associated blade linkage andmachine frame while additionally the blade is quickly and preciselypositioned for consecutive rapid cycling.

The suitable braking of a veneer clipper blade permits driving'of theblade at an accelerated speed since the rebound problem is overcome bythe present brake mechanism. As blade speed is inversely proportional tothe time the blade is in obstructive, cutting contact with the veneerribbon, the greater the speed the less ribbon travel is impeded. Asearlier mentioned this contact time is one of the limiting factors ofthe speed at which a veneer ribbon may travel past a clipper. Thepresent ribbon speed with prior art braking devices is in the area of300 feet per minute or five feet per second which speed may be increasedsubstantially by clippers equipped with the instant brake mechanism.

The foregoing advantages of the brake mechanism are realized withoutjeopardizing acceptable cutting tolerances. Obviously the closer the cutto the optimum cutting line the greater the veneer saving with anacceptable cutting tolerance now beingapproximately one-half inch forcurrent scanning and clipper equipment.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a front elevational view of a conventional wood veneer clippermachine equipped with a pair of the instant brake mechanisms,

FIG. 2 is a vertical elevational view taken along line 2-2 of FIG. 1showing one side of a brake mechanism,

FIG. 3 is a view similar to FIG. 2 taken along line 3- 3 of FIG. 1 withfragments broken away for convenience of illustration,

FIG. 4 is a vertical elevational view taken along line 4-4 of FIG. 3showing details of a clutch mounted lever in pivotal attachment with apair of arm members,

FIG. 5 is an elevational view of the opposite end of the clutch takenalong line 5-5 of FIG. 3 with a quadrant broken away,

FIG. 6 is a view of the clutch taken along irregular line 6-6 of FIG. 5,and

FIG. 7 is a side elevational view of a typical brake I component of thepresent invention with a quadrant broken away and parts positioned forpurposes of illustration.

DESCRIPTION OF THE PREFERRED EMBODIMENT With continuing reference to theaccompanying drawings wherein applied reference numerals indicate partssimilarly identified in the following specification, the referencenumeral 10, in FIG. 1, indicates generally a veneer clipping machine,termed a clipper by those in the art, and shown located transversely ofthe path of a veneer ribbon to be severed by the machine.

Typically, a veneer ribbon, subsequent to being cut from a peeler log,is dimensioned in its travelling direction by passage through a clippermachine as at 10. The ribbon is continuously presented to the machine bya series of powered conveyor belts with suitable hold down means bearingon the veneer ribbon holding same in planar contact with said belts.Additionally, existing clippers include wheel means or the like incontact with the passing veneer ribbon for the purpose of initiating asignal for clipper operation after the passage of a predetermined lengthof veneer with said means being settable according to the desiredlength. More recently, and in addition to the above, veneer clippershave been operated in conjunction with infra-red and other type scanningsystems which detect unsuitable veneer segments and initiate a signalfor clipper operation.

The clipper machine 10, as shown in FIG. 1, includes a reciprocallymounted blade 11 adjustably secured to a blade bar 12 the lattercomprising part of the machines toggle linkage which mounts blade 11 forreciprocative movement. The ends of the blade bar 12 mount sleeves l3slidably engaging guides 14 which serve to assure the blade moving inparallel with a cutting anvil 15 over which the veneer ribbon at Vcontinuously moves.

- appropriate electrical signal to a solenoid valve 18,

results in the toggle linkage moving from its position shown through acenter position wherein toggle linkage is aligned resulting in a cuttingstroke of blade 11 with continuing linkage movement past centerresulting in the upstroke of blade 11 to complete one cycle. The

. present brake mechanism, as it will become evident, is

equally adaptable to clippers using other types of blade linkagearrangements and is not dependent upon the particular linkage shown. Theforegoing description of a clipper and associated equipment is wellknown and is provided in the interest of background material only anddoes not constitute part of the present invention.

With attention now directed to the present invention, a pair of brakemechanisms are indicated generally at 20 in FIG. 1 with each mechanismbeing identical except as later noted. A weldment type housing servesjointly as a base for securement to a clipper frame member 10A and tomount a pair of brake components, indicated generally at 25, on oppositehousing members 22. Each member 22 is apertured at 22A. As seen in FIGS.2 and 3, members 22 are spaced by a mounting block 23 which is suitablysecured to machine frame member 10A. In instances where the brakemechanism is to be incorporated into a clipper machine frame, thehousing may be dispensed with and instead, later described brakecomponents directly mounted to the clipper.

Disposed intermediate the housing members 22 are clutch means indicatedgenerally at 24 carried by a shaft 26 interconnecting the clutch withbrake components 25 of a single brake mechanism.

With specific attention to clutch means 24, as best disclosed in FIGS. 2through 6, the particular clutch means shown and described is of thetype termed a cam clutch in that in one direction internal clutchelements move to interengage the clutch members for torque transmissionwhile in an opposite direction said clutch elements will disengage topermit clutch overrunning. Such clutches operate in similarity to aratchet and pawl mechanism with the exception that the number of engagedrelationships between the driving and driven clutch members areinfinite. On such suitable clutch, later described, is that manufacturedby the Morse Corporation and termed a PB series cam clutch.

For translating and reciprocating motion of blade 1 1 into rotationalclutch motion I provide a pair of arms 30 pivotally attached to theclipper blade bar 12. Said arms terminate upwardly in pivoted attachmentto a clutch mounted lever 32 as best seen in FIG. 4. The arms 30straddle linkage 17 in a spaced manner. A bolt assembly 33 and bushing33A pivotally couples the upper ends of arms 30 to lever 32 which inturn is integral with a clutch mounted collar 34. Collar 34, milled at34A for toggle linkage clearance, is in keyed engagement as at 35 withone end 36A of a clutch driving member 36. A bearing sleeve 36B permitsindependent rotation of said driving member and shaft 26. Interiorly ofcup shaped driving member 36 are a series of cam elements 37 which serveto permit overrunning movement in one direction of driving member 36relative to a driven clutch member at 38 while rotation of cup member 36in an opposite direction imparts a rocking action to the cam elements 37causing same to interengage said clutch members for transmitting rotarymotion to driven member 38. The directional arrows applied to FIG. 5indicate overrunning and engagement directions as noted. Such clutchesare available with the cam elements 37 arranged so as to reverse theoverrun and engaged directions as would be the case for the clutchcomponent of the brake mechanism at the right hand side of the clipperas viewed in FIG. 1.

During movement of blade 11 downwardly the pair of arms follow topartially rotate or index clutch member 36 the latter moving in anunrestricted manner freely about shaft 26. The reversal of blade 11, asit initiates its upstroke, imparts opposite rotational movement to theimmediately above mentioned components causing cam members 37 to rockinto clutch locking engagement for conjoint rotation of its driving anddriven members.

Driven clutch member 38 is provided internally with a keyway at 40receiving an elongate key 41 carried by shaft 26 which extends to theouter end of shaft 26 to thereat provide keyed engagement at 42A ofshaft 26 with a friction plate 42 of brake component 25. The same keyarrangement also pertains to the opposite end of shaft 26 and theopposite brake component 25.

The following description of a single brake component 25 is equallyapplicable to both brake components 25. One suitable brake component isthat manufactured by the Horton Corporation identified as model no.LWB-8212. With joint reference to FIGS. 2 and 7 a typical brakecomponent of the present mechanism includes a stationary annular brakering 43 which at all times is in biased braking engagement with acoacting annular surface 44 of the ribbed friction plate 42. Airpressure is admitted to the interior of a brake mounting plate 45 via aport 46 served by a pressure conduit 47. A pressure regulator at 48(FIG. 1) permits the air pressure to be set as desired which in turndetermines the internal pressure exerted against a pressure plate 49 andultimately the degree to which brake ring 43 is biased against surface44 of the friction plate 42. During clipper machine operation the brakering 43 and surface 44 are at all times in biased surface contact. Thesetting of pressure regulator 48 would be made to best suit the specificclipper machine.

Completing the brake description, retainer means at 50 in conjunctionwith helical springs 51 bias the pressure plate 49 to a brake release oropen position in the absence of system air pressure within the brake.Suitable bearing means at 52 serve to rotatably support the frictionplate 42 which in turn supports the outer end of shaft 26.

The operation of the instant brake mechanism has been set forth inconjunction with the foregoing description hence further operativedescription is believed unnecessary. In some clipper installations theuse of one brake mechanism 20 may be adequate.

While but one embodiment of the present invention has been set forth itis not intended to so restrict the scope of the protection but ratherthat such extend to all forms of the invention coming within the breadthof the appended claims.

What I claim and desire to secure under a Letters Patent is:

1. A brake mechanism for the braking of the return stroke of anintermittently operated reciprocative blade of a cutting machine, saidmechanism comprisclutch means having a driving. member and a drivenmember and including means permitting said driving member to overrun inone direction while interengaging said members during rotation of saiddriven member in an opposite direction,

brake means associated with the cutting machine and including a movablefriction plate,

means interconnecting said driven member of the clutch component and themovable friction plate for imparting rotational movement to the latter,and

means extending intermediate the driving clutch member and the blade andactuated by the latter to impart rotational movement to said drivingclutch member, movement of the last mentioned means during the return ofthe blade resisted by said brake means whereby the inertia of the bladeand moving machine parts is dissipated to prevent rebound motion of theblade from its rest position.

2. The brake mechanism as claimed in claim 1 wherein said brake meanscomprises a pair of brake components each having a movable frictionplate, said interconnecting means comprising a shaft in engagementadjacent its opposite ends with each of said friction plates.

3. The brake mechanism as claimed in claim 2 wherein said firctionplates are at all times in surface engagement with stationary brakemembers with the latter resisting friction plate movement.

4. The brake mechanism as claimed in claim 2 wherein said brakecomponents each include a pressure plate and a brake ring, said pressureplate biasing said ring into engagement with said friction plate, saidbrake components adapted to receive pressurized air from a regulatedsource to act upon said pressure plate whereby the biased engagement ofsaid brake ring with the pressure plate may be set to achieve thebraking action desired.

5. The brake mechanism as claimed in claim 2 wherein said shaft issupported at its ends within said friction plates, said driving anddriven members carried by said shaft with said driven member mounted forrotation independent of said shaft, said driven member including aclutch mounted collar having a lever appendage for pivoted engagementwith the upper end of said means extending intermediate the drivingclutch member and the blade.

6. A brake mechanism for braking a reciprocative blade of a clippingmachine during the blades return to a position of rest, the blade havinga cutting stroke and a return stroke constituting one cycle of bladeoperation, said brake mechanism comprising,

clutch means having a driving member and a driven member and includingmeans intermediate said clutch members permitting overrunning of saiddriving member during one direction of rotation and serving to engagesaid clutch members during rotation in an opposite direction,

brake means supported by a machine and including coacting stationary andmovable members,

means interconnecting said driven member of the clutch means with themovable member of said brake means,

means coupling said blade to the driving member of the clutch means forimparting movement to said driving member in an overrunning directionduring the cutting stroke of the blade and oppositely imparting oppositeclutch engaging movement to said driving member during the return strokeof the blade, and

the movable member of said brake means cooperating with said stationarybrake member to dissipate inertia of the blade and associated machinestructure throughout the return stroke of the blade so as to preventrebound motion of the blade from its rest position.

7. The brake mechanism as claimed in claim 6 additionally including ahousing secured to a machine frame member, said brake means comprising apair of brake components mounted on said housing and each having amovable friction plate, said interconnecting means comprising a shaft inengagement adjacent its opposite ends with said friction plates.

8. The brake mechanism as claimed in claim 7 wherein said frictionplates are at all times in surface engagement with stationary brakemembers with the latter resisting friction plate movement.

9. The brake mechanism as claimed in claim 8 wherein said brakecomponents each include a pressure plate and a brake ring, said pressureplate biasing said ring into engagement with said friction plate, saidbrake components adapted to receive pressurized air from a regulatedsource to act upon said pressure plate whereby the biased engagement ofsaid brake ring with the pressure plate may be set to achieve thebraking action desired.

10. The brake mechanism as claimed in claim 7 wherein said shaft issupported at its ends within said friction plates, said driving anddriven members carried by said shaft with said driven member mounted forrotation independent of said shaft, said driven member including aclutch mounted collar having a lever appendage for pivoted engagementwith the upper end of said coupling means.

11. In a wood veneer clipper machine having a reciprocative bladeintermittently operated through a cutting cycle including a cuttingstroke and a consecutive return upstroke to a rest position, linkageintermediate the blade and a frame member of the machine, a power sourcefor blade operation, the improvement comprising a brake mechanismhaving,

clutch means supported by said housing and including a driving memberand a driven member,

means coupling said driving member to said blade and imparting rotationin opposite directions to said driving member during reciprocative blademovement,

brake means mounted on said machine,

means operatively connecting the driven clutch member with said brakemeans,

said clutch component including means disengaging said clutch membersduring rotation of said driven member in one direction and interengagingsaid members during opposite rotation of said driving member, and

said opposite direction of the driving member coincident with theupstroke of the blade whereby the upstroke of the blade and associatedmachine linkage is braked to dissipate inertia of blade and linkage toassure a non-rebound return of the blade to its uppermost rest position.

12. The brake mechanism as claimed in claim 11 additionally including ahousing mounting said brake means to a machine frame member, said brakemeans comprising a pair of brake components each having a movablefriction plate, said interconnecting means comprising a shaft inengagement adjacent its opposite ends with each of said friction plates.

. The brake mechanism as claimed in claim 12 wherein said frictionplates are at all times in surface engagement with stationary brakemembers with the latter resisting friction plate movement.

14. The brakemechanism as claimed in claim 13 wherein said brakecomponents each additionally include a pressure plate and a brake ring,said pressure plate adapted to be biased by pressurized air within saidbrake components to urge said brake ring into forceful contact with saidfriction plate whereby said contact may be varied for brake adjustingpurposes by regulating the air pressure.

15. The brake mechanism as claimed in claim 12 wherein saidshaft issupported at its ends within said friction plates, said driving anddriven members carried by said shaft with said driven member mounted forrotation independent of said shaft, said driven member including aclutch mounted collar having a lever appendage for pivoted engagementwith the upper end of said coupling means.

1. A brake mechanism for the braking of the return stroke of anintermittently operated reciprocative blade of a cutting machine, saidmechanism comprising, clutch means having a driving member and a drivenmember and including means permitting said driving member to overrun inone direction while interengaging said members during rotation of saiddriven member in an opposite direction, brake means associated with thecutting machine and including a movable friction plate, meansinterconnecting said driven member of the clutch component and themovable friction plate for imparting rotational movement to the latter,and means extending intermediate the driving clutch member and the bladeand actuated by the latter to impart rotational movement to said drivingclutch member, movement of the last mentioned means during the return ofthe blade resisted by said brake means whereby the inertia of the bladeand moving machine parts is dissipated to prevent rebound motion of theblade from its rest position.
 2. The brake mechanism as claimed in claim1 wherein said brake means comprises a pair of brake components eachhaving a movable friction plate, said interconnecting means comprising ashaft in engagement adjacent its opposite ends with each of saidfriction plates.
 3. The brake mechanism as claimed in claim 2 whereinsaid friction plates are at all times in surface engagement withstationary brake members with the latter resisting friction platemovement.
 4. The brake mechanism as claimed in claim 2 wherein saidbrake components each include a pressure plate and a brake ring, saidpressure plate biasing said ring into engagement with said frictionplate, said brake components adapted to receive pressurized air from aregulated source to act upon said pressure plate whereby the biasedengagement of said brake ring with the pressure plate may be set toachieve the braking action desired.
 5. The brake mechanism as claimed inclaim 2 wherein said shaft is supported at its ends within said frictionplates, said driving and driven members carried by said shaft with saiddriven member mounted for rotation independent of said shaft, saiddriven member including a clutch mounted collar having a lever appendagefor pivoted engagement with the upper end of said means extendingintermediate the driving clutch member and the blade.
 6. A brakemechanism for braking a reciprocative blade of a clipping machine duringthe blades return to a position of rest, the blade having a cuttingstroke and a return stroke constituting one cycle of blade operation,said brake mechanism comprising, clutch means having a driving memberand a driven member and including means intermediate said clutch memberspermitting overrunning of said driving member during one direction ofrotation and serving to engage said clutch members during rotation in anopposite direction, brake means supported by the machine and includingcoacting stationary and movable members, means interconnecting saiddriven member of the clutch means with the movable member of said brakemeans, means coupling said blade to the driving member of the clutchmeans for imparting movement to said driving meMber in an overrunningdirection during the cutting stroke of the blade and oppositelyimparting opposite clutch engaging movement to said driving memberduring the return stroke of the blade, and the movable member of saidbrake means cooperating with said stationary brake member to dissipateinertia of the blade and associated machine structure throughout thereturn stroke of the blade so as to prevent rebound motion of the bladefrom its rest position.
 7. The brake mechanism as claimed in claim 6additionally including a housing secured to a machine frame member, saidbrake means comprising a pair of brake components mounted on saidhousing and each having a movable friction plate, said interconnectingmeans comprising a shaft in engagement adjacent its opposite ends withsaid friction plates.
 8. The brake mechanism as claimed in claim 7wherein said friction plates are at all times in surface engagement withstationary brake members with the latter resisting friction platemovement.
 9. The brake mechanism as claimed in claim 8 wherein saidbrake components each include a pressure plate and a brake ring, saidpressure plate biasing said ring into engagement with said frictionplate, said brake components adapted to receive pressurized air from aregulated source to act upon said pressure plate whereby the biasedengagement of said brake ring with the pressure plate may be set toachieve the braking action desired.
 10. The brake mechanism as claimedin claim 7 wherein said shaft is supported at its ends within saidfriction plates, said driving and driven members carried by said shaftwith said driven member mounted for rotation independent of said shaft,said driven member including a clutch mounted collar having a leverappendage for pivoted engagement with the upper end of said couplingmeans.
 11. In a wood veneer clipper machine having a reciprocative bladeintermittently operated through a cutting cycle including a cuttingstroke and a consecutive return upstroke to a rest position, linkageintermediate the blade and a frame member of the machine, a power sourcefor blade operation, the improvement comprising a brake mechanismhaving, clutch means supported by said housing and including a drivingmember and a driven member, means coupling said driving member to saidblade and imparting rotation in opposite directions to said drivingmember during reciprocative blade movement, brake means mounted on saidmachine, means operatively connecting the driven clutch member with saidbrake means, said clutch component including means disengaging saidclutch members during rotation of said driven member in one directionand interengaging said members during opposite rotation of said drivingmember, and said opposite direction of the driving member coincidentwith the upstroke of the blade whereby the upstroke of the blade andassociated machine linkage is braked to dissipate inertia of blade andlinkage to assure a non-rebound return of the blade to its uppermostrest position.
 12. The brake mechanism as claimed in claim 11additionally including a housing mounting said brake means to a machineframe member, said brake means comprising a pair of brake componentseach having a movable friction plate, said interconnecting meanscomprising a shaft in engagement adjacent its opposite ends with each ofsaid friction plates.
 13. The brake mechanism as claimed in claim 12wherein said friction plates are at all times in surface engagement withstationary brake members with the latter resisting friction platemovement.
 14. The brake mechanism as claimed in claim 13 wherein saidbrake components each additionally include a pressure plate and a brakering, said pressure plate adapted to be biased by pressurized air withinsaid brake components to urge said brake ring into forceful contact withsaid friction plate whereby said contact may be varied for brakeadjusting purposes by regulating the air pressure.
 15. The brakemechanism as claimed in claim 12 wherein said shaft is supported at itsends within said friction plates, said driving and driven memberscarried by said shaft with said driven member mounted for rotationindependent of said shaft, said driven member including a clutch mountedcollar having a lever appendage for pivoted engagement with the upperend of said coupling means.